Rotary pump



D09 3 -1929- l 1. P. BARLow 1,738,345

ROTARY PUIP Filed Aug. 20, 1928 Hull l ma

Patented Dea 3, 1929 UNITED sTATEs PATENT OFFICE LESTER I. ARLOW, OF DETRQIT, MICHIGAN ROTARY PUMP Application illed August 20, 192B. Serial No. 300,711.

rial No. 254,222, filed February 14, 1928, and

Cil

has for its object to provide in a rotary pump means for relieving excess of pressure on the discharge side of the pump so that onl a predetermined pressure will be maintain at whatever speed the pump may be driven. A further object of the invention is to provide means for returning excess of fluid from the discharge side to the inlet side of the pump by a relatively short passage of such size as to be free from retardation of the flow by friction. A further object of the invention is to provide a return passage for excess of fluid from the discharge side to the inlet side whichwill be wholly within the pump structure. A further object of the invention is to provide means by which the permitted pressure on the discharge side of the pump may be readily regulated.

With the objects above indicated and further objects hereinafter explained in view my invention consists in the construction and combination of elements hereinafter described and claimed.

Referring to the drawings:

Figure 1 is a horizontal sectional view of a rotary pump having my invention embodied in it.

Figure. 1n is a transverse sectional view taken on line 1-1a of Fig. 1.

Figure 2 is a perspective view of the back plate, port plate and race ring showing these elements separated.

Figure 3 is a perspective view of the outer face of the back plate, and

F' ure 4 is a view of the outer end of the pump.

In the drawing 1 indicates the pump casing within which fits race ring 2 between the inner wall 4 and the back plate or plug 3. Through the inner wall 4 extends shaft 6 which carries rotor 5 Within the casing, the bearing for shaft 6 being eccentric to the race ring. In the rotor 5 are formed a plurality of radial slots 5a each adapted to receive a roller piston 8 and Vpermit it `to have free movement therein.

9 and 10 indicate respectively the inlet and discharge openin s in the casing or housing 1 on opposite si es of the rotor and to the rear of race ring 2. Fitting within the rear end of the casing is back plate or plug 3 having formed in its front face, that is the face towards the rotor 5, a recess 11 extending from near the vertical line passing through the centre of the plate to the perlphery of the plate to communicate with inlet opening 9. Also in the inner face of the back plate 3 but on the other side of the vertical line passing through the centre of the plate is a recess 12 shaped as shown extending to the periphery` of the plate in communication with the discharge opening 10. The back plate or plug is preferably cast with recesses 11 and 12. The outer :tace of the back plate is ma chined or otherwise finished `and the portions of the inner face between recesses 11 and 12 are also machined or otherwise finished, and between the ends of recess 11 a post 13 is left to support the port plate 14 which lies against the inner finished face of the back late. Port plate 14 is of sheet metal pre erably of brass of suitable thickness which forms the inner wall for recesses 11 and 12, and has formed in it suitable openings constituting the ports by which the fluid operated on by the pump is led to and from the chamber in which the rotor rotates.

Near its periphery port plate 14 is provided on the inlet side with a series of openings 17 arranged close together and forming practically a continuous opening for admission of fluid from recess 11 to the rotor chamber from near the upper end of the vertical line through the centre of the chamber to its lower end. Also on the inlet side, port plate 14 is provided near-its centre with arcuate o eniner 15 providing open communication t rougliout its length with the sides of the slots of the rotor near their inner ends.

On the discharge side plate 14 is provided near its periphery with openings 18 arranged close together to form a practically continuous openingr from the lower to the upper end of recess 12 for outflow of liquid from the rotor chamber to the 'discharge opening 10. Also in the discharge side, the plate is provided with an arcuate opening 16 providing open communication throughout its length between the recess 12 and the ends of the slots of the rotor near their inner ends. v

Port late 14 is held in place on the inner face of )ack plate 3 by dowel pins 19.

The Openings 15, 16, 17 and 18 may be readily formed by dies with the accuracy required so that there is no necessity for forming the recesses 11 and 12 in the back plate with the accuracy which would be required if they formed the ports, it being necessary only that the recesses be so formed as to leave a solid body of metal between them and to be so formed as to be in communication with the openings in port plate 14.

At a suitable point, preferably on the horizontal line through the centre of the plate an opening 2O is formed through the rear face of back plate or plug 3 on the inlet side. On the same horizontal line on the discharge' side is formed an opening 21 adapted tol receive the stem of a valve 22. Concentric with this opening 21 in the rear face of the back plate is formed a circular recess 23 having at its periphery valve seat 24. An arcuate opening 25 concentric with opening 21, and between it and the valve seat 24 is formed through the back plate to permit fluid to pass from recess 12 to the back of the back plate when the valve is open.

The back plate or plug 3 is held in the pump casing 1 by cover plate 26 secured to the casing by screws or bolts extending through the peripheral flange 27. The inner edge of this peripheral flange extends inward over the open rear end of the casing a suilicient distance to engage the edge ofthe back plate to hold it in the casing. From the inner edge of peripheral flange 27 a ring 28 extends rearward so that vthe main part of the cover plate is spaced away from the rear face of back plate 3 so as to provide a chamber 29 ail'ording free passage of fluid from the discharge side of the pump as it is released by valve 22 to opening 20 and the inlet side. In line with the centre of valve 22 the cover plate is pro! vided with a rearwardly extending recess 30 -to receive the outer end of a coiled spring 31, the other end ofwhich bears against Valve 22 to hold the valve normally to its seat. This spring 31 is of such strength as to hold the valve to its seat so long as the pressure on the discharge side does not exceed the pressure desired. When the pressure exceeds that desired the valve yields permitting the excess of fluid to pass freely back through chamber 29 and through opening 2() to the inlet side. By reason of the relatively large size of chainber 29 and the 'short distance between the opening to the discharge side and the opening to the inlet side the friction of a long bypass is avoided. This distance is less than one half the radius of the back plate or plug 3 and is shorter than the pumping stroke of the pump. The cupped shape of the cover plate 26 affords a chamber of relatively large capacity considerably greater than that of the openings in the back plate or plug. This chamber 29 will, in operation, be filled with a body of fluid greater in volume than the volmne of the liquid to be by-passed so that not only is the distance through which this liquid to be bypassed very short but its movement is through a body of liquid. 'Ihe resistance due to the weight of a long column and to friction with the walls of the passage through which it must pass is thus reduced to a minimum.

The pump chamber is preferably'providcd on its inner side with a plate 32 as a lining plate for Wall 4. This plate has an opening 33 for shaft 6.

Having thus described my invention what I claim is 1. In a rotary pump having a cylindrical chamber for the rotor, a rotor provided with radial slots each having a piston movable therein, an inner wall having an opening therethrough for the shaft of the rotor, a back plate having inlet and discharge openings Aformed therein, an opening through said plate on the inlet side, an opening through the plate on the discharge side, a cover plate covering the outer face of the back plate having its mid portion recessed so as to form a passage between the openings in the back plate.

2. In a rotary pump having a cylindrical chamber for the rotor, a rotor provided with radial slots each having a piston movable therein, au inner wall having an opening therethrough for the shaft of the rotor, a back plate having inlet and discharge openings formed therein, an opening through said plate on its inlet side, an opening through the plate on its discharge side, a poppet valve for controlling the discharge opening, a spring bearing against the outer face of the valve, a cover plate covering the outer face of the back plate having its mid portion recessed so as to form a passage between the inlet and discharge openings in the back plate, the cover plate being provided with a recess to receive the'outer end of the spring.

3. In a rotary pump, a casing having a cylindrical chamber formed therein open at its outer end, a plate against the front wall of the chamber having an opening therein near`its centre, a race way ring having its forward end against said plate, a port plate against the outer edge of the race ring, a rotor carryingradially movable pistons iu the space between said plates enclosed by the race ring, a back plate within the casing against the port plate having inlet and discharge passages formed therein on the side facing said port plate and means for holding the back plate and race ring in position Within the casing.

4. In a rotary pump, a casing formed to rovide a rotor chamber, a rotor therein and liaving radial slots, piston elements in said slots, a race ring in the chamber about the rotor and against which the piston elements work, a pair of plates engaging said ring on opposite sides and spaced thereby, one of the the outer side of the back plate for connect- P ing the openings therein,'and normally restrictive valve means for controlling the liow of liquid through the cover.

5. In a rotary pump, a casing formed to provide a rotor chamber closed on one side and open on its other side, a rotor in said chamber and having radial slots, piston elements movable in said slots, a plate fitting Within the opening on the open side of the easing and formed to 'have inlet and discharge passages inthe side of the plate facing the rotor, a pair of openings extending through said plate, one at the inlet passage and the other atthe dischargepassage, means on the outer side of the plateand forming a by-pass connection between said openings, and valve means for controlling the ovv of fluid through said by-pass. v

6. In a rotary pump, a casing formed to have a rotor chamber closed on Vone side and open on the opposite side, a rotor assembly in said chamber, a plate fitting Within the opening on the open side of the chamber, said plate having inlet and discharge passages formed therein on the side facing the rotor assembly, a pair of openings extending through said plate, one at the inlet passage and the other at the discharge passage, means providing a by-pass connection on the outer side of said plate for said openings, valve means for controlling the flow of fluid.

thrcmgh said by-pass, and means interposed between the rotor assembly and the plate for controlling the timing ot the pump.

7. In a rotary pump, a casing having a chamber therein provided with intake and discharge openings, Wall members for the chamber on opposite sides of the same, a. rotor assembly in the chamber between said wall members for displacing iiuid through the pump, one of said Wall members having intake and discharge passages formed therein on the side of the member facing the rotor assembly, openings extending through said last named Wall member, one at the inlet passage and the other at the discharge passage,

means providing a chamber on the outer side of said wall member and providing a by-pass connection for said Wall member openin s, said chamber having an area many times t e combined area of the openings so as to permit a free and unobstructed flow between the openings, and the valve means for controlling thc flow through the by-pass.

8. A puln comprising a casing having a chamber wit inlet and discharge openings, a rotor assembl Within said chamber for displacing fluid t ierethrough, and means providing a by-pass circuit for the ump through said chamber for controlling t e delivery of the pump at the discharge opening, said by'- pass having a capacity in excess of that of the delivery of the pump and being shorter in length than the pumping stroke of the ump.

9. A pump comprising a 'casing having a chamber with inlet and discharge openings, a rotor assembly in said chamber for displacing fluid through said pump, means providing a by-pass circuit for said chamber, and port means in the chamber between the rotor and the by-pass to determine the pum ing stroke of the rotor, said by-pass circuit aving a capacity in excess ot that for the delivery of the pump and having a length shorter than the pumping stroke of the pump as determined by said port means.

10. A pump comprising a casing having a chamber closed 0n one side and open on the opposite side, a rotor assembly in said chamber for displacing fluid therethrough, said chamber having intake and discharge openings, and means providing a detachable closure for the open side ot the chamber, said closure providing a by-pass Icircuit for said chamber, said circuit having a capacity in excess of that ot the delivery of the pump and being shorter in length'than the pumping stroke of the pump.

11. As an article of manufacture for use in a rotary pump of the vane type, a plug having inlet and discharge passages formed therein on one side and openings extending through the plug from one side to the other, one opening communicating With the inlet passage, and the other opening with the discharge passage.

l2. As an article ot manufacture for use in a rotary pump ot the vane type, a plug having inlet and discharge passages formed therein on one side, and openings extending through the plug, one communicating with each of said passages, said plug having a valve seat formed about one of the openings.

13. An assembly of the character described for use in a rotary pump ot the vane type, comprising a plug having inlet and discharge passages formed therein on one side, openlugs extending through the plug from one side to the other, there being an opening at each of said passages, a valve for controlling loP the flow of iuid through one of the o enings, and a port late having orts disposed to control flow o fluid to and iiom the pump chamber supported by the plug on the side thereof which is provided with the inlet and discharge passages.

14. An assembly of the character described for use in a rotar pump of the vane type, comprisinnr a plug aving inlet and discharge assages iormed therein on one side, openmgs extending through the plug from one side to the other, a valve for controlling the flow of fluid through one of the openings, a port plate having ports adapted to control {iow of liquid to and from the rotor chamber and discharge passages supported by the plug on the side thereof which is provided with the inlet and discharge passages, said plug having its side faces substantially parallel.

15. An assembly of the character described for use in a rotary pump of the vane type, comprising a plug having passages formed therein on one side adapted to communicate with the .intake and discharge ports of the pump, openings extending through the plug from one side to the other, there being an opening for each passage, and a valve for controlling flow of fluid through one of the openings, said valve seating against the side of the plug opposite that in which the inlet and discharge passages are formed.

16. An assembly of the character described for use in rotary umps of the vane type, comprising a plug aving inlet and discharge passages formed therein on one side, openings extending through the plug from side to side, there being an openin for each passage, a valve for controlling ow of iiuid through one of the openings, said valve seatin against the side of the plug opposite the i e in which the intakeand discharge passages are formed, and means formed in the plug to support and guide the valve.

17. An assembly ofthe character described for use in a rotar pump of the vane type, comprising a plu aving inlet and discharge passages orme therein on one side and opening through said side and the periphery of the plug, openings extending through the plug from one side to the other, one for each of said passages, a valve for controlling flow of fluid through one of said o enings, said plug being provided with a tu ular portion at said last named opening to provide a suport and a guide for the valve with the said ast named opening extending partway about the guide, and a port plate having ports adapted to control flow of iiuid to and from the said inlet and discharge openings supported by the plug and fitting against the side thereof through which the intake and discharge passages open, said guide terminating short of the port plate.

18. In a rotary pump, a casing having inlet and discharge openings and a cylindrical chamber for the rotor, a rotor in said chamber provided with radial slots each having a piston movable therein, said casing having a Wall member on one side of the rotor having an opening through it for the shaft of the rotor, a back plate for the rotor chamber on the opposite side of the rotor having inlet and discharge passages in communication with the inlet and discharge openings of the casing and in communication with the rotor chamber, and a valve controlled by-pass between the discharge and inlet passages of said back plate.

19. In a rotary pump, a casing having inlet and discharge openings and a cylindrical chamber for the rotor, a rotor provided with radial slots each having a piston movable therein, said casing having a wall member on one s1de of the rotor havmg an openmg through it for the shaft of the rotor, a back plate for the rotor chamber on the opposite side of the rotor having inlet and discharge passages in communication with the inlet and discharge openings of the casin and in communication with the rotor cham er, and a bypass between the discharge and inlet passages of said back plate, a valve controlling said bypass and a spring tending to hold said valve in closed position.

` 20. In a rotary pump a casing having inlet and discharge openings and a cylindrical chamber for the rotor, a rotor provided with radial slots, each having a piston movable therein, said casing having a Wall member on one side of the rotor having an opening through it for the shaft of the rotor, a back plate for the rotor chamber on the opposite side of the rotor having in one face thereof inlet and discharge passages in communication with 'the inlet and discharge openings of the casing, andin communication with the rotor chamber, an opening through said back plate on the inlet side of the pump, and an opening on the discharge side so arranged that said openings are separated on the opposite sides of said plate by a distance less than one half the radius of said back plate, and a regulating valve between the two openings through the back plate.

21. In a rotary pump a casing having inlet and discharge openings and a cylindrical chamber for the rotor, a rotor provided with radial slots each having a piston movable therein` the casing having a wall member on one side of the rotor having an opening through it for the shaft of the rotor, a back wall member on the opposite side of the rotor chamber having inlet and dischdrge passages in communication with the inlet and discharge openings of the casing and in columunication with the rotor chamber, an opening through said back Wall member on the inlet side of the pump and an opening through it on the discharge side, and a cover plate extending over said openings to form between it and the outer face of the back wall plate a bypass passage between said openings, and a valve controlling said bypass.

22. In a rotary pump, a casing having inlet and discharge openings and a cylindrical chamber for the rotor, a rotor provided with radial slots each having a piston movable therein, the casing having a wall member on one side of the rotorhaving an opening m through it for the shaft of the rotor, a back wall member on the opposite side of the rotor chamber having inlet and discharge passages in communication with the inlet and discharge openings of th'e casing and in communication with the rotorl chamber, an opening through said back wallf member on the inlet side of the pump and an opening through-it on the discharge side, and a cover plate eX- tending over said openings to form between 2@ it and the outer face of the back wall member a by-pass passage between said openings and a valve controlling said by-pass, said cover plate being so dished as to leave between it and the rear face of the back plate a chamber of greater capacity than that of the openings in the back plate.

In testimony whereof, I hereunto aix my signature.

LESTER P. BARLOW. 

